мPhysiological Assessment of Miners’ Noise Exposure and Measures for Its Prevention

Abstract

Introduction: To solve the tasks of preventing occupational diseases in workers of the mining industry, it is important to substantiate physiological indicators of tension of the regulatory systems of the human body under the negative impact of industrial noise and neuro-emotional work intensity and to assess the effectiveness of hearing personal protective equipment (PPE). Our objective was to identify physiological characteristics of adverse functional changes in workers of various professions in the mining industry exposed to the combined effect of occupational noise and work intensity to substantiate the use of hearing protection devices. Materials and methods: We studied indicators of concentration of attention, short-term memory, speed of perception of visual and auditory signals, and the index of functional changes in the circulatory system reflecting negative effects of occupational noise exposure combined with work intensity on the central nervous and cardiovascular systems. We assessed occupational noise exposure by the equivalent sound level on the A-scale of a sound level meter per shift, work intensity, and conducted physiological studies of mining industry employees. Results: In miners, we established a 5.6-fold decrease in concentration of attention from the initial level and a 5.9-fold increase in the index of functional changes in the circulatory system compared with operators of robotic complexes, in which all indicators varied within the physiological norm. The maximum change in the parameters indicates the work tension that was the most pronounced in miners. The same extent of workplace stress was observed in operators of mineral processing plants and engineering and technical staff exposed to similar noise levels (60-70 dB, sometimes exceeding 90 dBA), while the lowest one was observed in the operators of robotic complexes, thus indicating maintenance of a sufficient level of working capacity during the work shift. The estimated miners’ index of functional changes in the circulatory system (2.69±0.08 points) demonstrated the state of functional stress. The individual analysis indicated a significant percentage of people with reduced unsatisfactory adaptation and the state of its failure (3.0±0.05 points) in this very professional group. According to the results of establishing a causal relationship between the increase in the functional tension by indicators of the central nervous system and cardiovascular system and occupational noise levels, emotional stress and adverse shift mode, the workplace stress was justified as a marker of the combined effect of noise and intensity of the work process. Conclusions: A high level of workplace stress accompanied by intensive occupational noise and work intensity factors is an indicator of a decreasing working capacity and development of a prognostically unfavorable functional state of the human body.